Centrifugal marine propeller

ABSTRACT

Marine propellers having helical blades are enshrouded in and integral with tapered shells which convert radially moving water to axially moving water, and also minimize turbulence.

v Unlted States Patent 1191 1111 3,826,591 w11s6n 1 1 July 30, 1974 [54] CENTRIFUGAL MARINE PROPELLER 2,616,511 11/1952 Perrott 416/193 [76] Inventor: Ernest V. Wilson, Green Acres 3x322 Traller (31-, 1501 6th -r BQX 3,444,817 5/1969 'Caldwell 416/179 ux Grams Pass Oreg' 97526 FQREIGN PATENTS 0R APPLICATIONS [2.2] 1971 40,903 10/1929 Denmark 416/189 [21] Appl. No.2 210,959 68,426 11/1957 France 416/189 665,894 5/1929 France...... 416/189 Related r Data 1,726 1868 Great Britain 416/189 [631 Continuatiofi-in-part of Ser No. 117,830, June 2, 460,765 2/1937 Great Britain 416/189 1971. 597,273 8/1925 France 416/189 {211 1158!.JJJJJJJJJJJJJJ::JiJiJiJJiiJJJJJJJ.181173631 1112 Primary Examiner-Everette Powell, [58] Field of Search 416/177, 189, 179, 227,

416/231; 415/42 [57] ABSTRACT Marine propellers having helical blades are en- [56] References cued shrouded in and integral with tapered shells which UNITED STATES PATENTS convert radially moving water to axially moving water, 98,268 12/1869 Joyner 416/189 and also minimize turbulence, 464,898 12/1891 Rooke 416/189 UX 536,998 4/1895 Bennett 416/189 1 Claim, 8 Drawing Figures- 573,351 12/1896 Parker 416/189 1,092,960 4/1914 Taylor 416/189 2,270,615 H1942 Baldwin 416/189 pmmsnmom" I I 3 .826-.591-

- "mmznr-a WITNESS mw w fw 1 CENTRIFUGAL MARINE PROPELLER DESCRIPTION This invention relates to water propulsion devices and more particularly to the enclosed shield marine propellers of one unit construction. Enclosed propellers are known where the centrifugal force of thewater only acts on the tips of the blades. This blade action becomes less effective when the water rotates with the blades in the enclosed shell. No other direct or effective use has been made of the centrifugal force of the water acting on the tapered conical shell with the larger diameter tothe rear to utilize this centrifugal force as a propellant. The conventional propellers depend on the angular blade action on the water to propel the craft. Theprior enclosed shield propellers are not new in their present form where the blade action becomes I less effective as the water rotates more readily in an enclosed shield. No other direct or effective use has been made to reduce the swirl by diverting it rearwardly as a propelling force. The conventional propellers without the shield depend on the blade action on the water to propel the craft. This blade actioncauses some swirl on the water and it is more intense toward the tips of the blades. No efficient way has been found to control the water from spreading outward.

One object of the invention is to provide simple efficient propellers with embodiment of principles where the centrifugal force of the water acting on the tapered cone-shaped shell seeks the larger diameter to the rear and is expelled as a thrust to drive the water craft for ward.

Another object of the invention is to provide enclosed shell type propellers where part of the blade action driving the water rearward unites with the centrifugal force in a cooperative action in the same direction.

Another object of the invention is to provide a coneshaped shell having the larger end of the tapered shell to the rear to divert the water in that direction by centrifugal force. A further object of the invention is to provide compact propellers of unitary construction that will control the centrifugal force and divert it to the rear as a propelling force. y

Another object of the invention is to provide a simple compact submersible cone-shaped propeller utilizing centrifugal force to drive the water craft and adapt itself for use on outboard. and inboard motors.

A further object of the invention is to provide simple submersible propellers with the larger ends of tapered cone-shaped shells exposed to the rear to expel the water rearward by centrifugal force without the use of bulky enclosed centrifugal pumps with moving parts, bearings, packing glands, or jets.

Still another object of the invention is to provide simple submersible propellers that divert a major portion of the driving force from centrifugal force by having the larger end of cone-shaped shells exposed to the rear and yet retain a single unit construction where the blades and the shells revolve together in fixed relative positions.

Another object of the invention is to provide simple effective propellers including safety shields to protect swimmers and marine life.

Another object of the invention is to cause less rotation of the water by having openings in the form of cutout sections of the concave tapered shield for free inlet of the water and retain the equivalent of a full tapered concave shield within the thrust. side of the blades where the water is under working pressure.

Still another object of the invention is to efficiently control the water on the thrust side of the blades where the working load pressure is greater by preventing it from spreading outwards to the sides.

Another object of the invention is to retain and provide a tapered concave shield expanded rearwardly on the thrust side of the blades where the working pressure of the water is dense and prevent the water from spreading outward to the sides by diverting it rearwardly as a propelling force.

A further object of the invention is to provide a simple enclosed shield propeller that will scoop a fuller volume of water from the front and sides and cause less cavitation.

Another object of the invention is to provide a simple propeller assembly that will move the water out and yet divert the centrifugal force of the water out as a propellant.

Another object is to provide an efficient propeller unit where the centrifugal force combines with the blade action in a cooperative manner that contributes to the propelling force.

Another object of the invention is to provide a simple compact propeller design that will meet the needs of the manufacturer for die-casting or mass production means.

Still another object of the invention is to provide a one-piece efficient propeller assembly with a shield that will offer some protection to swimmers and marine life.

Another object of the invention is to provide a simple, efficient and useful propeller that will meet the needs of manufacturing and adapt itself for use on inboard or outboard water craft.

IN THE DRAWINGS FIG. 1 is a rear end elevation view of a propeller forming one embodiment of the invention;

FIG. 2 is a sectional view of the propeller of FIG. 1;

FIG. 3 is a fragmentary side elevation view of a stern section of a boat using an outboard motor with the propeller of FIG. 1;

FIG. 4 is a perspective view of the propeller of FIG.

FIG. 5 is a perspective view of the larger outlet end of a cone-shaped shell housing of the propeller of FIG. 1;

FIG. 6 is an enlarged fragmentary side elevation view of the propeller of FIG. 1;

FIG. 7 is a rear elevation view of a centrifugal marine propeller forming an alternate embodiment of the invention; and,

FIG. 8 is a horizontal sectional view taken along line 8-8 of FIG. 7.

Referring to FIG. 1, shell 12 houses a plurality of substantially identical blades 5 having their root ends firmly affixed to a cylindrical hub 9 and having the elongated blades from 10 to 7 in abutment with cone shell 2 to 4 secured and firmly affixed. As noted, the hub 9 is substantially conventional in design using a standard taper center bore with a keyway and a locknut on the smaller end.

6-inch diameter large end and a 3.8564-inch extremesmall end tangent length 4 inches and 15 taper on the sides of the shell 12.

For blade angle computations inch from each end and one at mid-section could be as follows:

mid-section with a circumference of small dia larger dia The blade angles in relation to the center line of the shaft are respectively: larger diameter of shell 5.732 blade angle 45; mid-section diameter 4.928 blade angle 40 42; smaller end diameter 4.124 blade angle 35 45. The inside edge of the blades 3 (FIG. 1) is computed on the same basis but is not considered too critical. It will be'noted the width of the trailing blade tips 7-6 is not more than half the diameter as illustrated in 2-4.

It will be noted the blade tips 7-6 do not intersect the center. The trailing end of the propeller is left open for easy access to the conventional nut to secure it on the shaft. This is not shown but is in the conventional manner.

There is no need for blade action in the center as the centrifugal force moves the water out faster along the shell 4 and the blade tips 6-7.

With reference to FIG. 4, the perspective view of the blade assembly shows the leading edge spiral along the cone-shell 2-4 to the outside tip 7. The root of the blade 8 may be recessed to position it on hub 9 on an angle and affixed by conventional means.

With reference to FIG. 5, there is shown a smooth, cone-shaped housing having a small inlet end and an expanded outlet end. The leading edge of the blade 10 is in abutment and affixed to the housing 2.

The trailing tip of the blade 7 spirals toits position on the housing 4 and is affixed in this position by permanent means as a unit. The general parts may vary according to the needs of manufacturing while still remaining within the true spirit and scope of the invention.

EMBODIMENT OF FIGS. 7 AND 8 A centrifugal marine propeller 28 forming an alternate embodiment of the invention includes helical blades 30 integral with a hub 38 having a shaft bore 39 and a keying portion (not shown). The hub and blades form a propeller portion. Tip ends 37 of the propeller are integral with a cup-like shell or shroud 42, which is of generally truncated spherical shape to very effectively convert centrifugally impelled water to a discharge direction axial of the propeller. Three generally triangular cut-outs or openings 46 are formed in the forward end of the shell with rounded junctures 32 with the forward tip portions of the blades and rounded junctures 37 with the tip ends of trailing edges 36 of the blades. Fillets 35 join the tip ends of the blades smoothly to the shell. The peripheral band forming the shell is wide adjacent leading edges 41 of the blades and is substantially narrower adjacent the trailing edges 36. i

The propeller 28 is rotated in a clockwise direction, as viewed in FIG. 7, and the blades 30 impart a partially axial, partially radially outward movement to the water entering the openings 46 and the spherical shell smoothly turns the radially moving water to axial movement to give forward thrust. The blades 30 spiral rearwardly and outwardly and increase in width as they so do until they are past the longitudinal midpoint. The forward edges 41 are convex and the rearward edges 36 are somewhat S-shaped.

What is claimed is: 1. A centrifugal propeller assembly comprising: a plurality of substantially identical blades,

each of said blades having a root end and a leading edge spiraled rearwardly to the trailing end, a hub attached to the root ends of the blades, and a shell fixed to the tips of the blades, the shell being generally spheroidal and tapering from a small inlet end forward to a large outlet end rearward, the shell being arcuately concave, the annulus defined by the shell being of one width at points adjacent the forward edges of the blades and being substantially narrower than said one width at points adjacent the trailing edges of the blades, the blades increasing in width from the hub to the central portions of the blades proceeding radially outwardly from the hub, A the outer tip end portions of the blades continuously curving radially outwardly to merge smoothly into the shell,

the forward edge of the shell forming continuations of the forward edges of the blades,

the forward edge of the shell curves in large radii forwardly and radially outwardly from the forward edges of the blades and the forward edge of the shell at any point never being forward of the adja cent portion of the blades,

each trailing edge of the blades being generally S- shaped with the portion of the trailing edge between the hub and the central portion thereof being concave and the portion of the trailing edge between the shell and the central portion thereof being convex. 

1. A centrifugal propeller assembly comprising: a plurality of substantially identical blades, each of said blades having a root end and a leading edge spiraled rearwardly to the trailing end, a hub attached to the root ends of the blades, and a shell fixed to the tips of the blades, the shell being generally spheroidal and tapering from a small inlet end forward to a large outlet end rearward, the shell being arcuately concave, the annulus defined by the shell being of one width at points adjacent the forward edges of the blades and being substantially narrower than said one width at points adjacent the trailing edges of the blades, the bladeS increasing in width from the hub to the central portions of the blades proceeding radially outwardly from the hub, the outer tip end portions of the blades continuously curving radially outwardly to merge smoothly into the shell, the forward edge of the shell forming continuations of the forward edges of the blades, the forward edge of the shell curves in large radii forwardly and radially outwardly from the forward edges of the blades and the forward edge of the shell at any point never being forward of the adjacent portion of the blades, each trailing edge of the blades being generally S-shaped with the portion of the trailing edge between the hub and the central portion thereof being concave and the portion of the trailing edge between the shell and the central portion thereof being convex. 